Electric plug



May 19, 1942.

ELECTRIC PLUG Filed Oct. 6, 1937 INVENTOR EEDRGE EATD N. BY

A'ITORNEB,

e. EATON 8 4 I Patented .May 19, 1942 star QFFlCE.

ELECTRIC PLUG George Eaton, Cleveland, Ohio, assignor to May 0. EatonThis invention relates to the art of electric plugs.

As is well known to those who are familiar with the art of electricplugs, the points of connection of the electric wire to the plug aresubjected to considerable strain and there is always the danger of thesewires becoming accidentally disconnected from the plug or at leastloosened. As a result, there is danger of sparking.

This situation has long been regarded by the insurance companies asconstituting a serious hazard and accordingly they required suchconnections to withstand a strain of twenty-five (25) pounds. Now it isunderstood that the underwriters have recently doubled this requirementby specifying fifty (50) pounds instead of twenty-five (25) pounds, asa, still further safeguard.

It is therefore the object of the present invention to devise anelectric plug embodying means for relieving the binding post connectionsof the strain to which they would otherwise be subjected.

A further object is to devise such a means that can be readily andcheaply manufactured and applied within the casing of the plug.

A still further object is to so construct such a device that it willalso still further improve the insulation of the plug at the point ofentrance of the electric wire thereinto.

Other objects will appear from the following description and claim whenconsidered together with the accompanying drawing.

Fig. 1 is a plan view of my improved device illustrating its intendeduse and with parts broken away;

Fig. 2 is a view taken on line 22 of Fig. 1;

Fig. 3 is a perspective view illustrating the assembly of my anchoringdevice prior to placing the same in the plug;

Fig. 4 is a sectional view of the anchoring device corresponding withthe showing in Fig. l but with'the wires removed;

Fig. 5 is a front elevation of the anchoring device; and

Fig. 6 is a rear elevation of the same.

It is to be understood that the present form of disclosure is merely forthe purpose of illustration and that there may be devised variousmodifications without departing from the spirit of my invention asherein set forth and claimed.

Referring to the accompanying drawing, the terminals 1 and 2, enclosedwithin the casing 3, are adapted to be attached to the prongs A of thefamiliar electric toaster or the like. As in the conventional type ofplug, the sections of the casing 3 are secured together by the bolts 5and 6.

The wires 1 and 8 of the electric cable are adapted to be connected tothe screws I0 and H on the rear ends of the terminals. The one end ofthe coiled wire sheath I2 is engaged between the end portions. of themembers of the casing, as will be understood.

My invention consists in providing a block or body of fibre or otherelectric insulating material in which I form tortuous passages for thewires 1 and 8. This block 13 has a seat provided therefor in thecompanion casing members so as to fit snugly therein without any othermeans being required for holding the same in place. The companionmembers of the casing are formed with space between the rear end of thecasing and the middle longitudinal rib 4 so as to snugly receive andhold the block l3 against longitudinal dislodgement; and the block ismade of proper dimension laterally of the plug so that it fits snuglybetween the sides of the casing. Thus the block is braced against anyserious movement.

The block l3, which in the present instance Each set comprises an oddnumber of passages, as will be evident, so that each wire enters therear of the block and emerges from the front thereof. These two sets ofpassages may be understood as being separated bythe middle partitionwall l3a. Each set comprises the inner passage l3b, the intermediatepassage 13c and the outer open passage l3d. In each instance, the spacel3e between the inner ends of the inner and intermediate passages [3band I30 is countersunk, as is also the space I3 between the outer endsof the intermediate passage I30 and outer open passage l3d. At thosepoints where the wires are bent about the partitions between theadjacent passages, these partitions have their edges curved so as toafford proper and effective bearing and binding surface engagement forthe wires.

As indicated in the drawing, those portions of the wires within thepassages of the block l3 are protected by their individual covering ofinsulation which is removed from only the extreme end portions forconnection to the binding posts or screws [0 and H.

After theindividual wires have been extended through the passages of theblock l3 in the manner indicated in the drawing, the ends of the wireswill be attached to the terminals, and then the block l3 and terminals Iand 2 and the sheath are placed in position between the casing memberswhich are then secured together.

As will be seen, the end portions of'the wires, as they leave the blockl3, are practically in line with the screws Ill and II; that is theextent of wire which would otherwise extend angularly from the apertureat the middle of the rear end of the casing to the binding screws whichare located considerably to the side of the middle of the casing, isarranged neatly in the pasages of the block or body [3; and furthermore,this arrangement provides an effective locking of the wires against allpossible danger of being pulled loose from their binding screws.

By virtue of the tortuous extent of the wires through the block or bodyl3 and the close arrangement of the passages, together with abrupt turnstherebetween, any pull applied to the cable will merely lock the wires 1and 8 in the block or body l3. Thus, the points of connection at It andl i are entirely relieved of the strain to which the cable might besubjected outside of the casing, The holding force of the block or bodyl3 will be the same as the strength of the block or body itself.

If so desired, the passages lad may be of closed form, like passagesI32) and 130; and, as above stated, there may be various modificationsin the form or design of this invention.

Another advantage of my present improved device is that it will preventthe terminal from being accidentally dislodged from their properposition within the casing 3. This is especally important in a certaintype of electric plug as herein disclosed.

Not only does the block or body l3 relieve the wire connections of thestrain to which they would otherwise be subjected, but the block or bodyl3 serves also as a means of increased insulation.

This improvement is not costly to manufacture and assemble and yet it isextremely efficient and dependable and easily meets the rigidrequirements of the underwriters as above referred to.

What I claim is:

An electric plug comprising a chambered insulation body longitudinallydivided into two sections, a plurality of terminals within said body forconnection of the electric wires thereto, said body having an aperturefor passage of the electric cable therethrough, and anchoring meanstransversely disposed within said body and between said aperture andterminals, for relieving said wire connections from any strain to whichthe electric cable might be subjected outside of said body, saidanchoring means comprising an insertable block of electric insulationmaterial having two companion sets of passages for the two wires, eachset having an odd multiple number of substantially parallel transverselyspaced communicating passages each extending in a direction lengthwiseof the plug so as to constitute a tortuous combined passage ofsubstantially reversed U-shape through which each wire extends andthereby cause a binding effect thereupon when subjected to tension, saidcombined passages both occupying substantially the same transverse planeand terminating at their outer ends at fixed points substantially to therear of their respective terminal connections, said block havingpolygonal shaped means of body engagement, and said body sections beingformed with a recess seat means of corresponding polygonal form anddimensions for receiving the polygonalshaped means of said block andsnugly seating the same therein, said recess seat means being formed inthe companion sections of the body so as to hold said block between saidbody sections and against movement longitudinally of the plug or in anyother direction when in assembly.

GEORGE EATON.

